To meet the demand for wireless data traffic having increased since deployment of 4G communication systems, efforts have been made to develop an improved 5G or pre-5G communication system. Therefore, the 5G or pre-5G communication system is also called a ‘Beyond 4G Network’ or a ‘Post LTE System’.
The 5G communication system is considered to be implemented in higher frequency (mmWave) bands, e.g., 60 GHz bands, so as to accomplish higher data rates. To decrease propagation loss of the radio waves and increase the transmission distance, the beamforming, massive multiple-input multiple-output (MIMO), Full Dimensional MIMO (FD-MIMO), array antenna, an analog beam forming, large scale antenna techniques are discussed in 5G communication systems.
In addition, in 5G communication systems, development for system network improvement is under way based on advanced small cells, cloud Radio Access Networks (RANs), ultra-dense networks, device-to-device (D2D) communication, wireless backhaul, moving network, cooperative communication, Coordinated Multi-Points (CoMP), reception-end interference cancellation and the like.
In the 5G system, Hybrid FSK and QAM Modulation (FQAM) and sliding window superposition coding (SWSC) as an advanced coding modulation (ACM), and filter bank multi carrier (FBMC), non-orthogonal multiple access (NOMA), sparse code multiple access (SCMA), and Low-Density Parity-Check (LDPC) coding as an advanced access technology have been developed.
A Massive Multiple Input Multiple Output (MIMO) system is advantageous in that factors degrading system performance, such as fast fading, inter-user interference, and inter-cell interference, can be eliminated by use of a simple linear precoder by installing tens of or hundreds of antennas at a Base Station (BS). To achieve the advantages of the massive MIMO system, the premise that the BS has knowledge of accurate channel information should be satisfied. Accordingly, a legacy massive MIMO scheme is performed in Time Division Duplexing (TDD) mode in which channel estimation cost is not affected by the number of antennas. However, the TDD mode has low frequency efficiency, relative to Frequency Division Duplexing (FDD) mode. That's why most of current commercialized communication systems support the FDD mode. Accordingly, there is a need for a technique for implementing massive MIMO in the FDD mode in consideration of compatibility with many current commercialized communication systems.
The above information is presented as background information only to assist with an understanding of the present disclosure. No determination has been made, and no assertion is made, as to whether any of the above might be applicable as prior art with regard to the present disclosure.